• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.3
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• pp.223-235
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• 2020

In this study, we propose an approach for calibrating the elevation of a DEM (Digital Elevation Model), one of the key data in realizing unmanned aerial vehicle image-based precision agriculture. First of all, radiometric correction is performed on the orthophoto, and then ExG (Excess Green) is generated. The non-vegetation area is extracted based on the threshold value estimated by applying the Otsu method to ExG. Subsequently, the elevation of the DEM corresponding to the location of the non-vegetation area is extracted as EIFs (Elevation Invariant Features), which is data for elevation correction. The normalized Z-score is estimated based on the difference between the extracted EIFs to eliminate the outliers. Then, by constructing a linear regression model and correcting the elevation of the DEM, high-quality DEM is produced without GCPs (Ground Control Points). To verify the proposed method using a total of 10 DEMs, the maximum/minimum value, average/standard deviation before and after elevation correction were compared and analyzed. In addition, as a result of estimating the RMSE (Root Mean Square Error) by selecting the checkpoints, an average RMSE was derivsed as 0.35m. Comprehensively, it was confirmed that a high-quality DEM could be produced without GCPs.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.29-41
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• 2020

PURPOSE: The aim of this study was to provide evidence for the treatment of Forward Head and Rounded Shoulder Posture (FHRSP) using posture correction exercises by comparing muscle activity and onset time around the neck and shoulder area during an arm elevation task. METHODS: The subjects were divided into FHRSP (21 persons) and non-FHRSP (19 persons) groups to measure muscle activity and onset time of muscle contraction. Wireless surface electromyography was used to assess the muscle activity and onset time of the right and left sternocleidomastoid (SCM), splenius capitis, anterior deltoid, middle deltoid, serratus anterior, upper trapezius, pectoralis major, and infraspinatus during an arm elevation task. After the pre-measurement, the participants performed the postural correction exercises, and then the post-measurement was conducted. RESULTS: After the posture correction exercises, there were significant differences in the muscle activity and onset time of all muscles in the FHRSP group. The results of the comparison of the muscle onset time during an arm elevation task demonstrated that after the postural correction exercises, the muscle onset time was significantly reduced in the right and left SCM and left splenius capitis, but there were no significant changes in the onset time of other muscles. CONCLUSION: The results of this study help us understand the change in muscle activities and muscle contraction onset time in a person with FHRSP when lifting the arm and suggest the relevant basis to apply the posture correction exercise in clinical settings.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.7
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• pp.550-559
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• 2017

In order to maintain communication while the vehicle is moving, satellite azimuth angle and elevation angle correction are needed in real time. The elevation angle correction affects the system G/T according to the variation of the external noise temperature flowing into the antenna. G/T is expressed as a ratio of power gain G to noise temperature T and is an important performance function required for antenna gain design. This paper aims to G/T analysis considering elevation angle change and the establishment of an antenna design procedure. For this purpose, the relationship between elevation angle and brightness temperature including rain attenuation was analyzed according to recommendation ITU-R P.372 radio noise. Next, an antenna was designed based on the analysis results and design procedure was verified by G/T measurement. Through this experiment, G/T according to elevation angle was confirmed, and the minimum antenna gain analysis and design procedure required in the system could be established.

• Archives of Plastic Surgery
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• v.40 no.3
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• pp.209-213
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• 2013

Background A cartilage wedge block and covering flap are standard procedures for firm elevation of the ear in microtia correction. However, using costal cartilage for elevation of the reconstructed auricle can be insufficient, and the fixed cartilage wedge block may be absorbed or may slip out. Furthermore, elevating covering flaps is time-consuming and uses up fascia, a potential source of reconstruction material. Therefore, we propose an innovative method using autologous onlay rib bone graft for auricular elevation of microtia. Methods From February 1995 to August 2012, 77 patients received a first stage operation with a rib cartilage framework graft. In the second stage operation, a small full thickness of rib bone was harvested through the previous donor scar. The bihalved rib bone was inserted into the subperiosteal pocket beneath the cartilage framework. Results The follow-up time ranged from 1 month to 17 years, with a mean of 3 years. All of the patients sustained the elevation of their ears very well during the follow-up period. Donor site problems, except for hypertrophic scars, were not observed. Surgery-related complications, specifically skin necrosis, infection, or hematoma, occurred in 4 cases. Conclusions Onlay rib bone graft used to elevate the reconstructed auricle is a more anatomically appropriate material than cartilage, due to the bone-to-bone contact between the bone graft and the temporal bone. Postoperative minor correction of the elevation degree is straightforward and the skin graft survives better. Therefore, reconstructed auricle elevation using onlay rib bone graft is a useful and valuable method.

• PNF and Movement
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• v.20 no.2
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• pp.215-222
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• 2022

Purpose: The purpose of this study was to compare the effects of passive scapular upward rotation and posterior tilt and active scapular posterior tilt on the muscle activity of the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA). Methods: Fifteen healthy subjects performed general arm elevation, arm elevation with passive scapular upward rotation and posterior tilt, and arm elevation with active scapular posterior tilt. For active scapular posterior tilt, the subjects were trained in this movement using visual biofeedback and a motion sensor. During each arm elevation condition, electromyography was used to measure the muscle activity of the UT, LT, and SA. The measured data were analyzed using a one-way repeated ANOVA. Results: LT muscle activity was significantly increased during arm elevation with active scapular posterior tilt compared to both general arm elevation and arm elevation with passive scapular upward rotation and posterior tilt (p < 0.05). SA muscle activity was greater during arm elevation with passive scapular upward rotation and posterior tilt than during general arm elevation (p < 0.05). There was no significant change in UT muscle activity among the tested arm elevation conditions (p > 0.05). Conclusion: Performing arm elevation with active scapular posterior tilt and performing arm elevation with passive scapular upward rotation and posterior tilt may be useful strategies for increasing muscle activation of the LT and SA, respectively.

• Korean Journal of Remote Sensing
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• v.15 no.4
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• pp.339-348
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• 1999

To extract value-added products which are important in scientific area and practical life, e.g. digital elevation models, ortho-rectified images and geometric corrected images, Satellite Technology Research Center at Korea Advanced Institute of Science and Technology has developed a satellite image processing software called "Valadd-Pro". In this paper, "Valadd-Pro" software is briefly introduced and its main components such as precise geometric correction, ortho-rectification and digital elevation model extraction component are described. The performance of "Valadd-Pro" software was assessed on 10m resolution 6000 $\times$ 6000 SPOT panchromatic images (60km $\times$ 60km) using ground control points from GPS measurements. The height accuracy was measured by comparing our results with 100m resolution $DTEDs^{1)}$ produced by USGS and 60m resolution DEMs generated from digitized contours produced by National Geography Institute. Also, to show the superior performance of "Valadd-Pro" software, we compared the performance with that of commonly used PCI$\circledR$ commercial software. Based on the results, the geometric correction of "Valadd-Pro" software needs fewer ground control points than that of PCI$\circledR$ software and the ortho-rectification of "Valadd-Pro" software shows similar performance to that of PCI$\circledR$ software. In the digital elevation model extraction, "Valadd-Pro" software is two times more accurate and four times faster than PCI$\circledR$ software.ccurate and four times faster than PCI$\circledR$ software.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.6
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• pp.55-65
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• 2019

Universal Soil Loss Equation (USLE) is to estimate potential soil loss and has benefit in use with its simplicity. The equation is composed of five factors, one of the factors is the slope length and steepness factor (LS factor) that is for topographic property of fields to estimate potential soil loss. Since the USLE was developed, many equations to compute LS was suggested with field measurement. Nowadays the factor is often computed in GIS software with digital elevation model, however it was reported that the factor is very sensitive to the resolution of digital elevation model. In addition, the digital elevation model of high resolution less than 3 meter is required in small field application, however these inputs are not associate with the empirical models' backgrounds since the empirical models were derived in 22.1 meter field measurements. In the study, four equation to compute LS factor and two approaches to determine slope length and steepness were examined, and correction factor was suggested to provide reasonable precision in LS estimations. The correction factor is computed with field area and cell size of digital elevation model, thus the correction factor can be adapted in any USLE-based models using LS factor at field level.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.5 s.23
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• pp.67-74
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• 2002

The geometriccorrection of a satellite imagery is performed by making a systematic correction with satellite ephemerides and attitude angles followed by employing the Ground Control Points (GCSs) or Digital Elevation Models (DEMs). In a remote area or an inaccessible area, however, GCPs are unavailable to be surveyed and thus they can be obtained only by reading maps, which are not accurate in reality. In this study, we performed the systematic correction process to the inaccessible area and the precise geometric correction process to the adjacent accessible area by using GCPs. Then we analyzed the correlation between the two geo-referenced Korea Multiurpose Satellite (KOMPSAT-1 EOC) images. A new geometrical correction for the inaccessible area imagery is achieved by applying the correlation to the inaccessibleimagery. By employing this new method, the accuracy of the inaccessible area imagery is significantly improved absolutely and relatively.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.211-214
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• 2007

With the recent development of spatial information technology, the relative importance of satellite image contents has increased to about 62%, the techniques related to satellite images have improved, and their demand is gradually increasing. Accordingly, a standard processing method for the whole process of collection from satellites to distribution of satellite images is required in many countries for efficient distribution of images and improvement of their utilization. This study presents the processor standardization technique for the preprocessing of satellite images including geometric correction, orthorectification, color adjustment, interpolation for DEM (Digital Elevation Model) production, rearrangement, and image data management, which will standardize the subjective, complex process and improve their utilization by making it easy for general users to use them

• Korean Journal of Remote Sensing
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• v.34 no.1
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• pp.127-139
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• 2018

The GOCI atmospheric correction overland surfaces is essential for the time-series analysis of terrestrial environments with the very high temporal resolution. We develop an operational GOCI atmospheric correction method over land surfaces, which is rather different from the one developed for ocean surface. The GOCI atmospheric correction method basically reduces gases absorption and Rayleigh and aerosol scatterings and to derive surface reflectance from at-sensor radiance. We use the 6S radiative transfer model that requires several input parameters to calculate surface reflectance. In the sensitivity analysis, aerosol optical thickness was the most influential element among other input parameters including atmospheric model, terrain elevation, and aerosol type. To account for the highly variable nature of aerosol within the GOCI target area in northeast Asia, we generate the spatio-temporal aerosol maps using AERONET data for the aerosol correction. For a fast processing, the GOCI atmospheric correction method uses the pre-calculated look up table that directly converts at-sensor radiance to surface reflectance. The atmospheric correction method was validated by comparing with in-situ spectral measurements and MODIS reflectance products. The GOCI surface reflectance showed very similar magnitude and temporal patterns with the in-situ measurements and the MODIS reflectance. The GOCI surface reflectance was slightly higher than the in-situ measurement and MODIS reflectance by 0.01 to 0.06, which might be due to the different viewing angles. Anisotropic effect in the GOCI hourly reflectance needs to be further normalized during the following cloud-free compositing.